Closure cap



E. CAPUCIO Nov. 9, 1965 CLOSURE CAP S Sheets-Sheet 1 Original Filed June '7, 1962 FiG.

(STEP 1) MOLD CAP {STEP 4) APPLY ADHESWE TO TUBE NECK (STEP 2) REMOVE MALE DIE AND SPRAY SiUCONE (STEP 3) MOLD FERRULE iN CAP (STEP 5) JOIN MOLDED CAP AND FERRULE ASSEMBLY TO TUBE NECK TO TUBE FILLING OPERATION INVENTOR EUGENE CAPUCIO B Y p E. CAPUCIO Nov. 9, 1965 CLOSURE CAP 3 Sheets-Sheet 2 Original Filed June '7, 1962 FiGo PEG. 5

INVENTOR EUGENE CAPUCIO BY MM A ORN CLOSURE CAP Original Filed June '7, 1962 3 Sheets-Sheet 3 FIG. 7

INVENTOR EUGENE CAPUCIO ATTORNEYS Original application June 7, 1962, Divided and this application Pv'Iar. 351,867

Ser. No. 200,882. 13, 1964, Ser. No.

3 Claims. (Cl. 22039) The present application is a division of pending application Serial No. 200,882 for Method of Capping and Product Thereof, filed June 7, 1962, by Eugene Capucio.

This invention relates generally to container closures and more particularly to a novel method of manufacturing cap closures, the product of the manufacturing method, and the method of affixing said caps to containers.

Conventional methods for capping containers such as toothpaste tubes, for example, generally require that the neck of the tube container be externally threaded or in the alternative that a separate threaded neck be attached to the tube. Thereafter, a threaded cap is screwed onto the neck to form a completed closure of the tube. The foregoing assembly operations are generally completed by automatic machinery on a production basis; however, the cap-screwing operation is subject to serious difficulties due to inherent limitations in present automatic assembly apparatus. By way of example, it is often difficult to thread a cap manually to a tube, since proper starting engagement of the threads and axial alignment of the cap and neck are essential prerequisities to success. Accordingly it is not surprising that in automated production assembly, the cap screwing operation regularly presents a problem due to malfunction, thereby requiring the rejection of caps and/or containers which have been damaged and a follow-up operation wherein the capping operation is effected manually.

In accordance with the present invention, I have devised a cap product and a container capping method which entirely eliminates the need for the aforementioned cap screwing operation and thus avoids the difficulties attendant therewith. A further advantage is that the present method completely eliminates any threading of the tube neck. In accordance with my method, a closure cap is molded with internal threads in the conventional manner, preferably of a heat moldable plastic. Next, the internal male portion of the cap molding die is removed and the interior of the cap is coated with a releasing agent which will inhibit the bonding or fusing of plastic to the interior of the cap during a succeeding molding operation. Such an agent may be, for example, a silicone spray. Thereafter, a second male die is located axially within the cap and an externally threaded ferrule is molded using the surrounding previously formed plastic cap as a female die. The plastic material used to form the threaded ferrule preferably has a lower fusing temperature than the plastic used to form the cap so that fusion of the cap and ferrule is prevented. Fusion is further inhibited by the use of the silicone spray coating which is applied to the interior of the cap prior to molding of the ferrule therein.

Following a satisfactory cooling period, the male die used during the second molding operation is removed leaving the cap and ferrule assembly threaded together so that they form an integral cap closure unit. The ferrule is molded to have an internal surface proportioned to receive and mate with the elongated neck of a container tube which is to be capped by the closure unit.

In the capping operation, the integral cap and ferrule assembly is simply pressed onto the mating tube neck 3215,67 Patented Nov. 9, 1965 and the contacting surfaces are bonded together by conventional bonding techniques. It will be appreciated by those skilled in the art that this capping method completely avoids the troublesome cap screwing assembly operation, it being noted that the cap is first unscrewed from the ferrule and the container by the user who wishes to dispense material therefrom.

Other features and advantages of my invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which:

FIG. 1 is a block-diagram identifying the several steps included in the capping method provided by my invention;

FIG. 2 shows the conventional molding of a plastic p;

FIG. 3 illusstrates the application of a coating to the interior of the cap;

FIGS. 4 and 5 illustrate the steps of molding the ferrule within the molded cap;

FIG. 6 shows the application of a bonding adhesive to the neck of the tube before capping;

FIGS. 7 and 8 illustrate respectively the tube and capping closure in partially assembled position and in fully assembled position With the cap removed; and

FIG. 9 shows an alternative continued wall ferrule and cap fully assembled to a tube.

Referring now to the drawings, FIG. 1 illustrates sequentially the steps of the capping method provided by the present invention. The first operation which is performed in carrying out the steps of the invention is to mold a tube cap, preferably of a heat-moldable plastic material, in the conventional manner by the use of a die having external female and internal male parts. This operation has been illustrated in FIG. 2 wherein a female die 10 having a generally frusto-conical interior wall surface is shown in fragmentary cross section. The die 10 may be, for example, one of a number of such dies which form part of a molding apparatus for the simultaneous manufacture of a plurality of caps. In accom plishing the cap molding operation, a male die member 11 defining threads 12 on its periphery in inserted axially within its female counterpart 10, thus defining a charge receiving chamber. In the illustrated embodiment, a gate connection 14 is located adjacent to the outer end of the male die 11 for the injection of a heated moldable plastic into the charge member. The molding of the cap is entirely conventional and it is understood that the construction of the die parts 10 and 11 is merely representative since other and equivalent structures (e.g., pressure molding) may be used in accordance with the invention.

After the charge chamber has received the moldable plastic, the latter is permitted to cool and harden and thereafter, the male die 11 is unscrewed from within the cap 15 leaving the latter retained within the female die 10. In certain applications it may be desirable to remove the cap entirely from both die parts, but for purposes of explanatory convenience and illustration, the cap is shown as remaining within the female die 10 throughout the entire molding process.

Referring to FIGS. 1 and 3, the next operation of the method after removal of the male die 11 is to spray r the interior wall surfaces of the completed cap 15 with a liquid silicone which will act as a releasing agent, that is, an agent which tends to inhibit adhesion or joining of molten plastics. This operation has been illustrated schematically by the insertion of a spray nozzle 16 within the cap 15.

After the spray coating has been applied, the cap 15 serves as a female die for molding a ferrule therein,

shown as step 3 of FIG. 1 and more specifically illustrated in FIGS. 4 and 5. In FIG. 4, a male die 17 having an external frusto-conical molding surface 17a, is inserted axially within the molded cap 15. A charge of heated fluid plastic is admitted to the charge chamber between the exterior surface 17a of the male die and the threaded surface of the cap 15 via 14. Advantageously, the plastic used to mold the ferrule 18 is selected to have, as one of its physical characteristics, a lower fusing or liquefying temperature than is characteristic of the plastic of the cap 15. The ferrule is molded at this lower temperature.

This selection of difierent fusing temperatures for the cap and ferrule coupled with the use of the parting material coating on the interior wall surfaces of the cap 15 inhibits bonding of the ferrule to the cap. Additionally, the plastic of the ferrule is advantageously selected to have a predetermined shrinkage characteristic during cooling such that a desired minimum clearance is maintained between the threads of the ferrule and of the cap after the parts have cooled.

With reference to FIG. 4, it will be seen that the die 17 defines a lower, abutment surface which forms as seen in FIG. 5, an annular shoulder 18a centrally within the ferrule.

After the ferrule 18 has been molded within the cap 15, the male die 17 is withdrawn to leave the completed integral closure unit 13 as shown in FIG. consisting of the cap with the ferrule 18 threaded internally within the cap.

The next step in the capping method (FIGS. 1 and 6) is to prepare the elongated neck 1% of the tube 19 to which the closure unit 13 is afiixed by applying adhesive thereto. For this purpose I have shown a wick or brush applicator 20 which is maintained saturated with a suitable adhesive. The neck 19a of the tube is brought into contact circumferentially thereof with the applicator 20 by an apparatus (not shown) constructed for this purpose.

Following the application of adhesive to the tube neck 19a, the closure unit 13 is attached to the tube by pressing the central opening in the ferrule down over the neck 19a. (See FIG. 7.) It will be noted that the internal wall surface of the ferrule has been formed to match the shape and size of the neck 19a so that a tight fit will result when the ferrule encompasses the neck. Thus, the neck 19a and ferrule 18 are each of frusto-conical shape defining an included angle of approximately 15. The tapered shape assists in piloting the neck 19a into the ferrule, automatically effecting axial centering of the neck and ferrule.

In the embodiment illustrated in FIGS. 7 and 8, the upper end of the neck abuts the lower surface of the shoulder 18a midway within the ferrule. In the embodiment illustrated in FIG. 9, a shoulder 18b has been formed within the ferrule 18' at the upper end thereof which forms an abutment surface for the upper end of the neck 1%. Otherwise the method of molding and the assembly of the cap and ferrule of FIG. 9 to the tube 4 19' is the same as has been described in the embodiment illustrated in FIGS. 2-8.

It should be mentioned that since the present method begins with the conventional molding of a tube cap followed by the molding of a ferrule within the cap in threaded engagement therewith, that it may be desirable, for purposes of economy or otherwise, to obtain caps already formed, and then by the use of appropriate apparatus, mold a ferrule therein in the manner described above. Furthermore, the ferrule may be secured to the neck of the container tubes by various other known mechanical bonding techniques. Gaskets may be used within the caps as required.

The method of the present invention is particularly advantageous since it entirely eliminates the cap-screwing operation presently used in the manufacture and assembly of tube closures and also eliminates the necessity of threading the tube neck. Additionally, by using the individual cap as a matrix for molding the ferrule assembled thereto as a unit, there is less opportunity for the cap and its mating threaded connection to the tube (i.e., the threaded ferrule) to be mis-ma'tched or inadvertently malformed, which can sometimes occur when the parts are separately manufactured.

It will be understood that the foregoing description is merely representative and relates only to particular embodiments. Therefore, in order fully to appreciate the spirit and scope of the invention, reference should be made to the appended claims in which I claim:

1. A closure for a container having a tubular elongated neck comprising the combination of a cap having internal threads and a generally tubular hollow externally threaded ferrule molded in threaded internal engagement with said cap, said ferrule having at least one open end and having an internal tubular dimension to receive said neck upon insertion of the latter axially within said ferrule through said open end.

2. A closure according to claim 1 in which both the cap and ferrule are of molded plastic with the plastic of the ferrule having a lower fusing temperature than that of said cap.

3. A closure for a container having a dispensing opening there in comprising the combination of a cap having internal threads and a generally tubular hollow externally threaded ferrule molded within said cap in releasable, threaded engagement with the internal threads thereof, said ferrule having an open end adjacent the open end of said cap adapted to be connected to said container about the opening therein.

References Cited by the Examiner UNITED STATES PATENTS 6/58 Scheswohl 21573 1/63 Shinichi Sawai 220-37 

1. A CLOSURE FOR A CONTAINER HAVING A TUBULAR ELONGATED NECK COMPRISING THE COMBINATION OF A CAP HAVING INTERNAL THREADS AND A GENERALLY TUBULAR HOLLOW EXTERNALLY THREADED FERRULE MOLDED IN THREADED INTERNAL ENGAGEMENT WITH SAID CAP, SAID FERRULE HAVING AT LEAST ONE OPEN END AND HAVING AN INTERNAL TUBULAR DIMENSION TO RECEIVE SAID NECK UPON INSERTION OF THE LATTER AXIALLY WITHIN SAID FERRULE THROUGH SAID OPEN END. 